Eraser and holder therefor



June 23, 1 c. IZURIETA CHIRIBOGA ERASER AND HOLDER THEREFOR Filed Jan. 13, 1956.

INVENTOR.

C IZURIETA CHIRIBOGA United States ,Patent O r r 2,891,510 Patented June 3, 9

This invention relates to a novel type of eraser and vtol'a holder adapted tohold thiseraser.

-"-Her'etofore it has been --necesary tom'ake eraser's, :par- 't-icularlyrhosewhich.areused .in erasing typedlmaterial, sufliciently thick and rigid so that they will not deform when enough pressure is exerted on them during use-t ojr ra ei h .impressiqnwhiqh is be limina The thickness necessary to accomplish this rigidity has resulted in an eraser in which, after an initially pointed edge is worn down, a rounded profile is presented which is not pointed enough to erase small characters, e.g. typewritten letters. The eraser thus becomes useless for fine work, and either must be discarded or sharpened by some appropriate sharpening means. In either instance, there is a waste of eraser material.

It is an object of the present invention to provide an eraser which overcomes the above-described deficiencies.

It is a further object of the present invention to provide an eraser having at least a portion thereof which is thin enough to have a sharp edge at all times, and yet which eraser is sufficiently rigid not to deform under the pressure necessary to erase the impression to be removed, particularly ink impressions made from a type writer ribbon.

It is a still further object of the present invention to provide an eraser and a holder therefor to enable the eraser to be grasped more readily, which holder has retaining means to hold the eraser in the holder which is releasable to permit moving a new portion of the eraser to a usable position.

Other and further objects of the invention will become apparent from the following specification and claims together with the accompanying drawing in which:

Fig. l is a perspective view of an eraser according to the present invention;

Fig. 2 is a perspective view of a modification of the eraser according to the present invention;

Fig. 3 is a perspective view of the eraser according to Fig. 1 after it has been used;

Fig. 4 is a plan view of a holder for the eraser of Fig. 1

Fig. 5 is a sectional view taken along 5-5 of Fig. 4;

Fig. 6 is an elevation view of retaining means for use with the holder of Fig. 4;

Fig. 7 is a plan view of a modified form of holder, and

Fig. 8 is an end elevation view of the holder according to Fig. 7.

As seen in the figures, the eraser 10 consists of two spaced parallel flanges 11 which are joined to each other by a transverse member, here shown as a web 12, which is attached to the flanges along the longitudinal central portions thereof. In the embodiment shown, web 12 is attached to the flanges along the central longitudinal axes thereof, in the manner of a structural steel member generally known as an I-beam.

It is not necessary that the flanges be parallel to each 2 I other. In the modification shown in .Fig. 2, the flanges 11' diverge from each other. The web 12' connecting the-flanges 11' is relatively narrow at one end, and .becomes wider 'toward'the opposite end. The eraser can be made of any conventional eraser material, although I prefer to use an abrasive impregnated rubber material which is commonly employed in making 'erasers for erasing both pencil and ink.

.In use, the points at the .ends of the flanges 1'1Jwi1l first-be worn off, and then the end 'of the web 12 will -be-worn to produce a pointed edge as shown in Fig; 3:. ;In practice, the web iismade thinner than rthe flanges, and-is sufficiently thin so that a pointed Ledge will always be-produced .on'the end :of the :web. The web-and flange structure produces sufficient rigidity of the eraser as a gwhole, however, so that despite the fact that the web ,portion'isquite thin,-the er aser has suflicient rigidity 'so .itha-t "it will .notsdeform substantially underrthe pressure exerted 1011 it during its use. i 1 i It may be desirable to providera holder forthe eraser t'o :facilit-ate -.grasping it. This. permits making the eraser iof :erasermaterial iwhich =is too soft :to provide suificient rigidity so as to resist deformation at all times, or of material which it is desired to keep clean during the use of the eraser. In this case, it has been found advantageous to provide a case 14 as shown in Fig. 4, to encase the eraser and to permit a portion thereof to protrude from the end of the case. The case 14 is provided with a hollow interior 15 which has substantially the same crosssection as the cross-sectional shape of the eraser 10. In the space of the hollow interior 15 corresponding to the web portion 12 on the eraser is positioned retaining means in the form of a pressure plate 16 whcih extends substantially the width of the web portion 12. A threaded bore 17 is provided in the case 14 in which is positioned a screw 18. The screw 18 is rotatably connected to the pressure plate 16. When the eraser 10 is in the case 14, the screw 18 is turned, forcing the pressure plate 16 against the web portion 12 of the eraser, forcing the web portion of the eraser against the Wall of the case 14. When the protruding end of the eraser 10 is worn, the screw 18 is loosened, a new portion of the eraser 10 withdrawn from the case 14, and the screw 18 again tightened.

Figs. 7 and 8 show a modified form of case in which there is provided a substantially cylindrical case 14' which has a narrowed portion 19 adjacent the front end thereof from which the eraser 10 protrudes. The portion 19 is smoothed into a substantially rectangular portion 20 surrounding the protruding end of the eraser 10. The substantially cylindrical case with the tapered front portion provides a holder which can be firmly gripped by the user, yet which fits comfortably in the users hand.

There has thus been provided an eraser which presents a sharpened edge at all times, yet is sufficiently rigid not to deform under the pressure exerted on it during its use. The edge of the eraser is thin enough so that it never needs to be sharpened, and all of the material therein is utilized in the use of the eraser. There has also been provided a holder for the eraser which provides a convenient means for the user to grip the eraser firmly during its use, and which supplements the rigidity of the eraser.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the forms hereinbefore described and illustrated in the drawings being merely preferred embodiments thereof.

Having thus disclosed the invention, what is claimed 15:

1. An eraser consisting of two spaced flanges and a web joining said flanges to each other, said flanges and said web each being rectangular in cross section, said Web being attached to said flanges along the central longitudinal aXes thereof, said flanges and web being of an abrasive impregnated rubber eraser material.

2. An eraser as claimed in claim 1 in which said flanges are parallel to each other.

3. An eraser as claimed in claim 1 in which said flanges diverge from each other.

4. In combination, an eraser comprising two spaced flanges and a web joining said flanges to each other, said Web being attached to said flanges along the central longitudinal axes thereof, said flanges and web being of a rubbery eraser material, and a holder comprising a case having a hollow interior with substantially the same cross-sectional shape as said eraser in which said eraser is positioned with one end thereof protruding from said case, and adjustable web retaining means in said case adjustable transversely of the length of said hollow interior for retaining the web in said case and holding said eraser therein.

5. A combination as claimed in claim 4 in which said retaining means comprise a press plate in the portion of .4 said hollow interior corresponding to the web of said eraser, and a screw rotatably connected to said plate, said case having a threaded bore therein in which said screw is positioned.

6. A combination as claimed in claim 4 in which said case is rounded and has a narrowed portion adjacent the end of the case from which said eraser protrudes, which narrowed portion is smoothed into a substantially rectangular shape surrounding the projecting eraser.

References Cited in the file of this patent UNITED STATES PATENTS D. 30,122 Stewart Ian. 31, 1899 101,015 Holms Mar. 22, 1870 423,238 Fowler Mar. 11, 1890 447,873 Hanirnann Mar. 10, 1891 1,550,770 Akira Aug. 25, 1925 1,658,831 Blakeley Feb. 14, 1928 2,057,792 Sakai Oct. 20, 1936 2,261,314 Vogel Nov. 4, 1941 2,439,162 Edwards Apr. 6, 1948 FOREIGN PATENTS 332,969 Italy Dec. 13, 1935 

